Patients with cancer undergoing chemotherapy often have diarrhea, which may result from their treatment or Clostridium difficile infection (CDI). CDI diarrhea is an important diagnosis that can be missed if nurses are not vigilant in their assessments. Treatment for CDI diarrhea is different than that of chemotherapy- or radiation-induced diarrhea. If CDI diarrhea is not treated, it can become life threatening in some patients.